Hard cemented carbide material



' Patented Dec. 4, 1934 UNITED STATES HARD CEMENTED CARBIDE MATERIAL Gregory J. Comstock, Edgewood, Pa., assignor to Firth-Sterling Steel Company, McKeesport, Pa... a corporation of Pennsylvania No Drawing. Application December 1, 1932,

. Serial N0. 645,238

' 2 Claims.

This invention relates to hard cemented carbide materials made by a cementing or, sintering process which are useful as cutting'tools, wire drawing dies, and the like.

5 The composition contains a predominant proportion of titanium carbide and lesser amounts of tungsten. carbide, tantalum carbide, and an auxiliary metal or metals such as cobalt, nickel and iron. The tungsten carbide is preferably present in a greater proportion than the tantalum carbide.

In my application Serial No. 6411762, ,filed November 8, 1932,;there is disclosed a hard cemented carbide composition containing tungsten carbide, tantalum carbide, titanium carbide, and an auxiliary metal such as cobalt, nickel or iron. In that application the principal abrasive con- I stituent is tungsten carbide, whereas in the present application the principal or predominant abrasive constituent is titanium carbide.

It has been found that where a powdered mixture containing a predominant proportion of titanium carbide, and lesser amounts of tungsten carbide and tantalum carbide, and also an auxiliary metal or metals such as cobalt, nickel or iron, is sintered or cemented, a tool can be produced which "has an exceptionally high capacity for cutting steel. The tool has a my heat conductivity and has a much less tendency to form the detrimental chip cavity behind the cutting edge of the tool than other cemented compositions known to the prior art. It produces a smooth or plenished cutwhen used in the high speed machining of steel. In the manufacture of the hard cemented carbide material, a powdered mixture containing a predominant proportion of titanium carbide and lesser amounts of tungsten carbide and tantalum carbide, and a metal or metals of the group consisting of cobalt, nickel and iron, is ground in a ball mill in accordance with the usual processv of preparing finely divided materials for sintering. Thereafter, the powdered mixture is either first compacted and then sintered, or heat and pressure may beapplied simultaneously in order to produce the hard cemented carbide composition. Y

The proportion. of titanium carbide used is between about 40% and 60% by weight of the whole mixture. The tungsten carbide may be between about 20% and 40%. The tantalum carbide may vary between 5% and 20%. The

That is, the percentage of titanium carbide is greater than any of the other carbidesor the auxiliary metals. In atypical example, the mixed powders which were sintered contained,-

. Percent Titanium carbide 46 Tungsten carbide.... 29.62 Tantalum carbide I. 12. 70 Cobalt 11. 68

lum may be substituted for the tantalum carbide..

Furthermore, metallic columbium or columbium carbide may be substituted for the tantalum carbide either entirely or in part. In the claims, the terms tungsten carbide and tantalum carbide are intended to include the metals or carbides which I have pointed out may be substituted for the tungsten carbide and tantalum car-' bide. Metallic titanium or an oxide of titanium such as titanium dioxide may be used to replace a small proportion, say up to 10%, of the titanium carbide. The composition may also contain,- in addition to the constituents which have already been mentioned, small proportions of metallic chromium or molybdenum or their carbides.

For purposes of illustration, I have set forth a typical analysis of a composition embodying my invention. It is to be understood, however, that the invention may be otherwise embodied and that the proportions of the constituents may vary within the scope of the following claims.

I claim: I

1. A hard cemented carbide material containing about 46% titanium carbide, about 29.62% tungstenv carbide, about 12.70% tantalum carbide, and about 11.68% cobalt.

2. A hard cemented carbide material consisting essentially of about 40% to-60% titanium carbide, about 20% to 40% tungsten carbide, about 5% to 20% tantalum carbide, and about 3% to 15% of a metal of the group consisting of cobalt, nickel and iron.

' GREGORY J. COMSTQCK.

cobalt, nickel or iron, or mixtures thereof, should I I be 'between 3% and 15%. The titanium carbide 55 always is present in predominating proportions. 

